Pilbara 2

PATTERNS OF EARLY LIFE: Created in a shallow pool on the early Earth over three billion years ago, these stromatolites represent a record of the most ancient life on Earth. They formed because colonies of microbes, as they grew, incorporated sediments from the water to create rocky structures. Found in Western Australia, the stromatolites take several different forms, including the slightly cone-shaped ones seen here resembling an egg carton. The structures shown in this picture are each about half an inch high. Astrobiologists study these enigmatic structures to gain a deeper understanding of the early environments in which life on Earth originated and evolved. Image Credit: Abigail Allwood